Well, that was a learning experience not just about where DNS servers put information when you query them with 'what are the NS records for this subdomain', but also on how some of our local DNS servers are configured. (In a way that kind of surprises me, for one of them.)
TIL that if you ask a parent authoritative server for NS records for a subdomain, they show up in the 'authority' section of the reply, not the 'answer' section. For (perfectly good) DNS reasons.
